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Incenter Geometry

Source:

November 25, 2015
geometryincentercircumcirclegeometric transformationreflectionalgebra

Problem Statement

Let II be the incenter of an acute-angled triangle ABCABC. Line AIAI cuts the circumcircle of BICBIC again at EE. Let DD be the foot of the altitude from AA to BCBC, and let JJ be the reflection of II across BCBC. Show DD, JJ and EE are collinear.
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